This study is the first stage of a statewide chlamydia prevention and control program. The study is a cross-section, clinic-based ivnestigation of the prevalence of chlamydia among women in selected counties in North Carolina. Counties are selected to be geographically diverse, with representation of urban and rural areas, and with sufficient staffing to facilitate the investigation. The target population is women living within similar areas of North Carolina. The study population wil include symptomatic and asymptomatic women attending the County Health Department STD and Family Planning Clinics in the selected counties. All women undergoing pelvic examination in these clincis will be eligible for participation. Participation will involve a questionnaire of risk markers and risk behaviors, pelvic examination, and screening for chlamydial infection by ligase chain reaction assay. In some cases, enzyme immune assay will also be used for screening. Prevalence of symptomatic and asymptomatic infection among women attending the clincs will be determined using these test results. Identification of screening criteria to be used in future prevention programs will be developed.